Manufacturers of devices often provide performance data for the devices. In particular, manufacturers of devices that consume supplies in producing output often provide data regarding rates of consumption of the consumables so that consumers can estimate operating costs for the devices. As an example, an automobile manufacturer may provide estimated miles per gallon ratings for fuel consumed by a car model so that a consumer can estimate fuel costs that will be associated with the car. The estimated miles per gallon ratings are obtained by the manufacturer through testing of the automobiles. The resultant ratings are dependent on the test conditions, and will likely be different for each individual automobile purchaser depending on their driving habits and conditions under which they drive.
Industries other that the auto industry also provide rates of supply consumption for producing output. As an example, a manufacturer of printers may provide an estimated cost per page, or “CPP” for operation of a given printer. This CPP rate is in large part a function of the marking agent consumed per page. Like the automobile manufacturer, the printer manufacturer determines this rate through internal testing.
Internal testing typically comprises the printing of a test page with a number of characters and/or images thereon. The test page is printed a multiplicity of times until a marking agent is expired. A marking agent consumption rate can then be determined by dividing the amount of marking agent consumed by the pages printed. The marking agent consumption rate is reported to users, often in the form of a CPP. For many business users of printers, these CPP rates are of critical importance as the business requires accurate cost accounting.
The reported marking agent consumption rate will of course correspond to the test page used by the manufacturer. That is, the consumption rate will depend on the marking agent coverage on the test page. Thus, actual consumption rates for consumers will vary from the reported rate depending on the consumer's actual usage conditions. In particular, the software application used to create the test page printed will affect the amount of marking agent coverage. As an example, a test page created using a word processor such as MS Word will likely consume a different amount of marking agent than a textually identical page created using a different word processor, such as WordPerfect. This is due to the formatting process the printer uses to transform an incoming print job data file into an image for printing.
This can be further illustrated by reference to the schematic diagram of the general printing process shown in FIG. 1. A user may create a page using an application on his computer 2, which may be, for example, a document made using Word. This page in the form of a print job data file 4 is then transmitted to the printer 6 for printing. When received by the printer 6, the file goes through a formatter 8. The formatter 8 generally comprises a software utility that transforms data files created by applications into files that the printer engine 10 can interpret for printing. Accordingly, the formatted data file is transmitted from the formatter 8 to the print engine module 10 for printing. The print engine module 10 may be generally thought of as the set of mechanical, processor, and controller components that accept an input formatted print job data file from the formatter and deposits corresponding images on a sheet of paper. The end result is a printed page 12.
The formatter 8 responds differently to different software applications. For example, for a textually identical page created using Word and created using WordPerfect, the formatter 8 very likely will cause different levels of marking agent to be used in printing the respective pages. This problem is most acute for color images, where the formatter must determine what hue, brightness, contrast, etc., to give an image. Additionally, applications for producing and processing color images may contribute further uncertainty to marking agent consumption levels.
As an example, assume a single color image file is imported into two different software applications. Without directing that any changes be made to the image, the two applications then are directed to produce a printed page of the image. Regardless of the changes introduced by the formatter, the printed images will likely be slightly different and consume different amounts of marking agent due to different proprietary processes that the software applications use to import and process the original image.
These conditions have resulted in numerous unresolved problems in the art. For printer consumers it is impossible to determine what particular test page patterns or what software application was used to create the manufacturer's test page. It is therefore impossible for printer consumers to determine whether they may expect higher or lower marking agent consumption rates than those published. There is also no practical way for a consumer to compare marking agent consumption rates between different manufacturers, or to confirm a manufacturer's published marking agent consumption rate.
Still another problem is related to consumers' ability to test their device's supply consumption rates over the life of a device. A printer's marking agent consumption rate may deteriorate as components become worn and less efficient. While a printer purchaser can determine a marking agent consumption rate of their own by printing a known number of pages with a known amount of marking agent, there is no way to accurately compare this self-determined rate to the manufacturer's published rates. There is thus no way for a consumer to determine if or by how much their marking agent consumption has changed since purchase of the printer.
Problems in the art likewise exist for manufacturers of printers. Because marking agent consumption is dependent on the formatter, printer manufacturers face the difficult and expensive task of having to retest printers every time a new formatter is introduced. Testing records and procedures must be documented and maintained by the manufacturer regarding marking rate yield tests.
These and other problems remain unresolved; and there is thus a need in the art for a method for determining consumable consumption rate data for devices.